The increasingly expanded static functionalities and dynamic statuses of the vehicle are displayed by means of measuring meters, for example, a speed meter, an engine speed meter, a fuel meter, an in-vehicle temperature meter, etc. The measuring meters of the general vehicle for showing measurement data are designed to fit for use habit of the driver, wherein all measuring meters are designed in the form of LCD panels, pointer type display panels, or digital simulated pointer type display panels. Consequentially, these measuring meters do not provide eye-catching warning effect for the driver.
A conventional technique discloses an electronic control loop that triggers a RGB light-emitting device by comparing and mixing lights and changes light-projecting sources with different colors by a microprocessor in accordance with setting values of the meters. The driver is aware of various warring messages through variation of the projected lights so as to prevent himself from danger. Accordingly, these pointer type meters achieve the purpose of controlling color.
The microprocessor disclosed in this conventional technique is for receiving pointer-shifting signals and outputting corresponding control programs stored in the memory to the electronic control loop by means of control, operation, etc. However, the function of receiving pointer-shifting signals means that this conventional technique must provide at least one electrical connection to the pointer. Nevertheless, the modern vehicle meter does not necessarily adopt the pointer as its indication tool. It may adopt the digital symbols. Moreover, the function of receiving pointer-shifting signals means that the microprocessor operates in accordance with the received pointer-shifting signals. In case the pointer has a breakdown or a malfunction, the display tool is totally not able to work. Furthermore, this conventional technique does not provide any warning-setting function for a measuring limit of a target position.